Authentication and identification are two central problems surrounding payment systems, cryptography, and the Internet. In most security applications that require human authentication or identification, a secure application (either local or remote) will need to obtain input from a human user. In particular, the input could be a personal identification number (“PIN”) or some other type of password. The PIN is a mechanism that tells the secure application that this is the correct person and will allow access or permit a transaction. Many times the communication between the application and the user may occur over an insecure channel. For example, the user's input may be entered using a computer keyboard, and the information sent to the application. Rogue applications or computer “hackers” can eavesdrop on this channel and could possibly obtain the user's PIN. This is especially relevant with regard to debit card transactions, where the PIN is the major identifier of the customer's identity. In order to have security for these types of transactions the PIN should not be sent in the clear.
One solution to this problem is to require the user to have a secure computational device that receives the PIN from the user and sends it in encrypted form to the application. Although this is an effective mechanism, it is less than optimal since it necessitates the use of an external hardware device.
Another solution is to use biometric identification. For example, retinal scans and fingerprinting have been used to determine identities with almost perfect certainty. However, these processes can be extremely expensive to set up and maintain.
Another solution is to require the human user to carry a small transparency with encoded data. See, e.g., Naor et al., “Visual Authentication and Identification,” Crypto (1997). The user identification process is composed of the following steps: (1) the application sends a random looking image to a display; (2) the user puts his transparency on top of the display; and (3) the combination of the displayed image and the transparency is read by the user but is unknown to an adversary that does not have the transparency. The user identifies himself/herself by sending an answer, which is a function of the combined image. This solution is also less than perfect since the user would have to carry around physical transparencies.
Yet another solution is to use a one-time password that expires after use. See, e.g., Lamport, “Password authentication with insecure communications,” Communications of the ACM, 24(11) (November 1981). A problem with this mechanism is that a user needs to constantly obtain new passwords for the purposes of authentication. One could imagine the problems associated with receiving new PIN numbers from your bank every time you wanted to withdraw cash from an ATM machine.
Still another solution is to use a challenge-response protocol in which the user and computer have a shared secret whereby the computer could ask the user a question that has a pre-defined answer (e.g., mother's maiden name). The user would respond with the answer and, if the correct answer is supplied, access may be granted. This system, however, does not solve the ultimate problem of sending authenticating information over an insecure channel. Once this information is sent “in the clear,” it can be copied and used to impersonate the real user.
The present invention provides systems and methods where a secure application can authenticate the identity of a human using a shared unique identification in combination with a randomly selected identification that is rendered to the user.